1. Field of the Invention
The invention relates generally to the board forming art and more specifically to a device adapted to lay-up relatively high solids slurries on a base sheet conventionally formed on a fourdrinier.
2. Description of the Prior Art
Secondary headboxes exist in the papermaking art and generally comprise a pressure system designed for delivering low solids slurries (typical paper stock) to a narrow nip opening from which the stock flows onto a base paper sheet being formed on a conventional fourdrinier wire. Commercially available secondary headboxes designed for use in papermaking have been found to be completely inadequate for handling the slurries containing high solids concentrations necessary in forming mineral fiber-board products having high density overlays.